ABC News’ Kathryne Solove reports:

Black cats and dogs have long been stigmatized by superstitions of bad luck, especially this time of year.  Animal shelters across the country say that these animals are being passed up for adoption and euthanized at alarming rates — all because of their black coats. 

This phenomenon is referred to as “Black Dog Syndrome.”

“Black dogs have a very difficult time getting adopted, and are euthanized at a staggering rate at many animal control facilities throughout the country,” according to the Glendale Humane Society in California. “The sad truth is, they are overlooked in favor of lighter-colored dogs.”

Although an official study has not produced any data to support that theory, it is widely accepted within the animal shelter community. 

“There is considerable anecdotal evidence which supports the idea,” said Kim Saunders, vice president of shelter outreach and public relations for Petfinder.com. ”We hear from Petfinder shelter and rescue groups repeatedly that their black dogs and cats take longer and/or are less likely to be adopted.”

Petfinder.com features an “Adopt-a-Less-Adoptable-Pet Week,” when a large portion of the highlighted animals have black coats.   

Though the consensus among shelters is that black-coated animals are at a disadvantage, the explanation for the trend varies. 

“There may be a stereotyped perception of black animals being equated with bad or evil – examples are black cats depicted as bad luck or black dogs as a bad omen in films - to a simple matter of being harder to see in a shelter run [or] cage,” Saunders said. 

Some feel that people are inherently afraid of black animals, while others attribute the lack of adoptions to the black fur not being as photogenic and, therefore, making them less marketable online. 

Others consider the idea of ”Black Dog Syndrome” deceptive, saying that the phenomenon can be explained by the simple fact that there are greater numbers of black dogs, inevitably making it harder for one to be adopted.  If there are more black dogs then others, then they are more likely to be euthanized. 

These animals are stuck with a stereotype riddled with negativity, but many shelter workers think that creative marketing can change that.

Shelters across the country are using costumes and professional photography to make black dogs and cats more appealing to potential adopters.  Through creative staging, they hope to show that black animals are just as adoptable and lovable as any other color or breed. 

“If you are thinking about adopting a dog, please don’t overlook black dogs,” the Glendale Humane Society says. “They are every bit as wonderful as lighter-colored dogs, and make just as loving and faithful companions.”